An ultra-sensitive electrochemiluminescence platform based on ZnONPs/Ni-foam and K2S2O8 for detection of chlorpyrifos

T4PPVB-COP composite-driven innovative electrochemiluminescence aptasensor for ultra-sensitive detection of chlorpyrifos

Herein, an enhanced electrochemiluminescence (ECL) aptasensor driven by a complex (T4PPVB-COP@CdS QDs) with large specific surface area and high stability was constructed for highly sensitive detection of chlorpyrifos (CPF), using electrostatic interactions and signal amplification techniques. In the presence of CPF, the specific binding between the aptamer and CPF caused partial detachment of the aptamer from the sensor, thus restoring the ECL signal. Notably, gold nanoparticles functionalized with streptavidin (SA) as signal enhancers further amplified the ECL signal in specific interactions with aptamers, thereby improving the sensitivity of the assay. Based on this, the proposed ECL aptasensor demonstrated significant detection performance for CPF with a linear range of 1-107 pg/mL and a LOD of 0.34 pg/mL. Furthermore, the feasibility of the ECL aptasensor was validated by the detection and analysis of CPF in real samples, which also provided a broad reference value for bioanalysis.

Recent advances in assessment methods and mechanism of microbe-mediated chlorpyrifos remediation

Chlorpyrifos (CP) is one of the Organophosphorus pesticides (OPs) primarily used in agriculture to safeguard crops from pests and diseases. The pervasive use of chlorpyrifos is hazardous to humans and the environment as it inhibits the receptor for acetylcholinesterase activity, leading to abnormalities linked to the central nervous system. Hence, there is an ardent need to develop an effective and sustainable approach to the on-site degradation of chlorpyrifos. The role of microbes in the remediation of pesticides is considered the most effective and eco-friendly approach, as they have strong degradative potential due to their gene and enzymes naturally adapted to these sites. Several reports have previously been published on exploring the role of microbes in the degradation of CP. However, detection of CP as an environmental contaminant is an essential prerequisite for developing an efficient microbial-mediated biodegradation method with less harmful intermediates. Most of the articles published to date discuss the fate and impact of CP in the environment along with its degradation mechanism but still fail to discuss the analytical portion. This review is focused on the latest developments in the field of bioremediation of CP along with its physicochemical properties, toxicity, fate, and conventional (UV-Visible spectrophotometer, FTIR, NMR, GC-MS, etc) and advanced detection methods (Biosensors and immunochromatography-based methods) from different environmental samples. Apart from it, this review explores the role of metagenomics, system biology, in-silico tools, and genetic engineering in facilitating the bioremediation of CP. One of the objectives of this review is to educate policymakers with scientific data that will enable the development of appropriate strategies to reduce pesticide exposure and the harmful health impacts on both Human and other environmental components. Moreover, this review provides up-to-date developments related to the sustainable remediation of CP.

Solid-state electrochemiluminescence sensor based on zeolitic imidazolate framework-67 electrospinning nanofibers for chlorpyrifos detection

A novel solid-state electrochemiluminescence (ECL) sensor for chlorpyrifos (CPF) detection was constructed based on zeolitic imidazolate framework-67 electrospinning nanofibers (ZIF-67 NFs). Silver nanoparticles (Ag NPs), ZIF-67 NFs, tris(2,2'-bipyridyl) ruthenium(II) [Ru(bpy)₃²⁺], and Nafion were successively deposited on the surface of the electrode. Ag NPs played a role in promoting electron transfer, and ZIF-67 NFs played a role in fixing Ru(bpy)₃²⁺ and promoting electron transfer due to its large specific surface area and porosity. Nafion formed a film on the outermost layer of the electrode to further improve the stability of the system. Therefore, the modified electrode showed stable and obvious ECL signal in PBS solution containing 10 μL 0.01 M TprA (pH 8.0). CPF quenched the ECL signal of the system, and the quenching value was linear with the logarithm of CPF concentration in the range 1.0 × 10^-13 to 1.0 × 10^-6 M. The detection limit was 3.3 × 10^-14 M (S/N = 3). In this study, ZIF-67 NFs were used as an ECL promoter for the first time, broadening the application range of ZIF-67 NFs.

Recent advances in electrochemical and optical sensing of the organophosphate chlorpyrifos: a review

Chlorpyrifos (CP) is one of the most popular organophosphorus pesticides that is commonly used in agricultural and nonagricultural environments to combat pests. However, several concerns regarding contamination due to the unmitigated use of chlorpyrifos have come up over recent years. This has popularized research on various techniques for chlorpyrifos detection. Since conventional methods do not enable smooth detection, the recent trends of chlorpyrifos detection have shifted toward electrochemical and optical sensing techniques that offer higher sensitivity and selectivity. The objective of this review is to provide a brief overview of some of the important and innovative contributions in the field of electrochemical and optical sensing of chlorpyrifos with a primary focus on the comparative advantages and shortcomings of these techniques. This review paper will help to offer better perspectives for research in organophosphorus pesticide detection in the future.

An enzyme-free electrochemiluminescence insulin probe based on the regular attachment of ZnO nanoparticles on a 3-D nickel foam and H2O2 as an efficient co-reactant

In this study, a highly sensitive, fast, and enzyme-free electrochemiluminescence (ECL) probe based on the decoration of zinc oxide nanoparticles on nickel foam is proposed for insulin determination. A silica film was employed as a size adjusting agent for the modification of the nickel foam surface with ZnO nanoparticles (ZnO NPs). The ECL of the ZnO NP/Ni foam was investigated in a natural medium in the presence of hydrogen peroxide (H₂O₂) as an efficient co-reactant. With increasing insulin concentration, a remarkable improvement in ECL signal was observed, which proved the enhancing effect of insulin on the ECL emission. The characterization of the ZnO-NP/Ni-foam electrode was performed via electrochemical impedance spectroscopy, Brunauer-Emmett-Teller (BET) surface area measurement, X-ray diffraction, field emission scanning electron microscopy (FESEM), and energy-dispersive X-ray analysis techniques. The fabricated electrode was applied for the trace analysis of insulin using the ultrasensitive ECL method in a phosphate buffer solution. Under the optimal conditions, the results showed excellent performance during insulin determination with a wide linear range of 3.57 × 10^-15 M to 2.94 × 10^-9 M, a low detection limit of 1.00 × 10^-16 M, and a relative standard deviation of 1.03%. The proposed ECL sensor with excellent reproducibility, long-term stability, and high selectivity was used for insulin determination in real serum samples with acceptable outcomes.

An enzyme-free electrochemiluminescence sensing probe based on ternary nanocomposite for ultrasensitive determination of chlorpyrifos

Herein, an innovative enzyme free electrochemiluminescence chlorpyrifos sensor was reported based on the incorporation of ternary nanocomposite (ruthenium nanobeads/silver nanoparticles/graphene oxide) on the surface of glassy carbon electrode. The silver nanoparticles as a robust signal enhancing agent were well deposited on the modified graphene oxide/glassy carbon electrode and exhibited supreme electrocatalytic proficiency. Then, Ru(bipy)₃²⁺ species in bead-like nanoparticles were uniformly anchored on the surface of the modified electrode with the help of chitosan, as a good crosslinking agent. Boron nitride quantum dots as a new coreactant species showed the excellent proficiency for signal enhancement of the fabricated electrode. The fabricated electrode was successfully used as an ultra-sensitive sensor for trace analysis of chlorpyrifos by ECL technique. The wide linear range and the low detection limit were obtained from 5.0 × 10^-15 to 4.2 × 10^-9 M and 6.5 × 10^-16 M, respectively.

A recent global review of hazardous chlorpyrifos pesticide in fruit and vegetables: Prevalence, remediation and actions needed

Pollution with pesticides is a widespread global problem and biomonitoring of the environment and human populations is necessary to assess potential harmful biological effects. One of the pesticides that are showing up in vegetables and fruit is chlorpyrifos (CPS). CPS is a nerve-poisoning organophosphorus insecticide, which is in up to 1/3 of all conventionally produced citrus fruits. Our review shows that CPS is a hazardous material that poses risks to human health and also pollutes the environment. There is numerous risk assessment of CPS reported, however, the assessment is easily affected by factors such as climate change, exposure period and CPS concentration. Therefore, rigorous update of the hazardous level of CPS is needed to determine the threshold level safe for humans and animals. There is a need for remediation using for example photoreactive nanoparticle methods and microbial degeneration possessing high degradation efficiency (73-97%). In addition, stringent biomonitoring of food, environment and human exposure should occur to avoid exposure to chemicals via citrus fruits and vegetables. This is necessary to assess health risks and socioeconomic impacts which also require collaboration between private and public sectors to facilitate the growth, sale and manufacturing of biopesticides.